Measurements of amylase in serum, urine, other body fluids and tissues have been used for many years as important aids in the diagnosis of a variety of conditions, especially acute pancreatitis. Amylases are usually measured in biological samples by measuring their ability to degrade starch or related compounds. Such assays measure not only amylases produced by the pancreas, but also those amylases produced by, e.g., salivary glands, fallopian tubes, etc. As a result, amylase may be increased in serum or urine when any of these other organs are diseased. This severely limits the diagnostic value of measuring amylase as an aid in the diagnosis of pancreatic disease.
There has been a longstanding need for a simple, rapid, specific method for the measurement of pancreatic amylases in biological samples. However, it has been difficult to distinguish the pancreatic and salivary amylases because of their close similarity. The amylases have been separated by electrophoresis, column chromatography and isoelectric focusing. However, these are, at best, slow and cumbersome. An inhibitor of salivary amylases has been found and applied to the measurement of pancreatic amylase. However, the inhibitor also inhibits pancreatic amylase to a lesser extent. Thus, the inhibitor method does not allow a direct measurement of pancreatic amylases. (We use the term "amylase" to indicate human alpha amylases.)
Therefore, it is an object of this invention to measure pancreatic amylases specifically in the presence of salivary and other amylases without interference from the salivary and other amylases that are closely related to salivary amylases.
It is also a further object of this invention to do this simply, cheaply and rapidly in order that this type of test may be utilized in any routine clinical laboratory set up.